Validity of the Training-Load Concept.

Area of Science:

• Sports Science
• Exercise Physiology
• Biomechanics

Background:

• Training load (TL) is crucial for athlete training prescription, monitoring, and injury prevention.
• Wearable technology has increased the use of TL metrics by researchers and practitioners globally.
• Conceptually, TL quantifies training dose to predict training effects.

Purpose of the Study:

• To critically evaluate the validity of current training load (TL) metrics.
• To investigate whether TL metrics accurately represent training dose and predict acute performance decrements.
• To identify fundamental problems in TL calculation, particularly the confounding effect of exercise duration.

Main Methods:

• Comparison of acute performance decrement following training sessions with established TL metrics.
• Analysis of how exercise duration influences the calculation and interpretation of TL metrics.
• Evaluation of total work done as a method for comparing training interventions with varying duration and intensity.

Main Results:

• Most current TL metrics are not consistent with their notional training dose.
• Exercise duration significantly confounds the calculation of many TL metrics.
• Total work done is an inappropriate metric for comparing training interventions that differ in duration and intensity.

Conclusions:

• There is a significant risk that fundamental issues in TL calculation are hindering advancements in training prescription and monitoring.
• Current TL metrics require critical evaluation by scientists and practitioners.
• Development of new, validated TL metrics is essential for accurate training prescription and monitoring.